This invention relates to a medical diagnostic ultrasound system and method for post-processing. In particular, a system and method for removing the effects of persistence and other post-processing is provided.
Ultrasound systems transmit acoustic waveforms and generate ultrasound data representing echo signals along a plurality of scanlines. The ultrasound data provided by receive beamformers undergoes various processes to generate an image on a display. These processes include focal gain compensation, dynamic range adjustment, various forms of filtering, display gray level mapping, and depth gain compensation.
For example, persistence processing or filtering is performed. Typically, an infinite impulse response (IIR) filter filters ultrasound data samples representing the same location at different times. This data is filtered as a function of one filter coefficient, typically labeled alpha (.alpha.). The amount of persistence may be changed as a function of the filter coefficient.
Ultrasound data altered by the various ultrasound image processes discussed above is used to generate an image and may be output to other devices, such as remote viewing stations or temporary or semi-permanent image storage memory. The ultrasound data is formatted for transfer to remote viewing stations. For example, the DICOM format is used. Pursuant to this format, the processed ultrasound data is provided with information indicating the patient, time of examination and various parameters indicating the type and amount of processing used to generate the transferred ultrasound data. Some of these descriptors are standard and some are added as proprietary variants. Processors at the remote viewing station use the ultrasound data to generate an image. The patient information and processing information is also displayed with the image. However, imaging the same region of the same patient with a different amount or types of ultrasound image processing may require the patient to be scanned again, requiring an expensive and inconvenient repeat examination.